How to properly insulate the roof along the rafters? Why and how to insulate a roof from the inside: detailed instructions

“... It came to insulation, I wondered about the right pie and realized that the roofers made a mistake during installation. What to do? How to insulate? — such desperate posts on FORUMHOUSE are not that uncommon.

“Attention - the right pie! – this is a comment from the witty guru of our portal, a professional roofer. – Take filo puff pastry, but you can also use “star” yeast-free dough. Roll it out, put the filling in the middle and fold the edges up, put it in a preheated oven... But if you are talking about a roof insulation cake, everything is as usual: steam, hydro, cotton wool.”

In this article we will talk about the correct roof insulation pie and how best to insulate the roof of a private house, which was built a long time ago, but everyone has not gotten around to converting a cold attic into an attic.

Types of roofs according to the method of insulation Methods of insulation What is the best way to insulate Why you can’t insulate a roof How to insulate a roof. Step-by-step instructions How to make attic insulation We insulate the roof correctly

Insulating a slate roof from the inside - All about insulation and energy efficiency

The attic of a residential building is a spacious room that should not sit idle in vain. Many owners equip there a full-fledged living room, office, workshop, etc.

To do this, it is necessary to insulate the roof; cosmetic repairs alone will not do.

In addition, roof insulation reduces the overall heat loss of the house by 15% , which is quite noticeable. Technologically, this process is not too complicated, but it will require some knowledge.

Let's try to figure out what operations need to be performed to insulate the roof. If you are planning a living space under a roof, we recommend that you read the article on insulating an attic roof.

Main types of roof structures

Most often, in private housing construction, traditional gable roofs , as the most profitable option in our latitudes. They are effective both in summer rains and in winter snowfalls, have been tested for centuries and are quite reliable.

Styrofoam

The use of polystyrene foam boards for insulating the roof of a residential building is considered very dangerous due to low fire resistance characteristics. It is best to use polymer materials when equipping non-residential premises. Equipping a building with foam plastic will cost much less. But it is best to use this material for external insulation of the walls of a house. For a flat roof, experts recommend using expanded clay.

This material is known for its fairly high thermal insulation qualities. This material consists of many small hot clay fractions that will gradually roll down. The use of expanded clay can be justified in the process of insulating pitched and flat roofs, floors and attic floors.

Insulating a slate roof

Tips for laying slate on a roof

It is recommended to use slate for roofing the flatst possible roofs with a minimum number of corners and various projections. The technology for installing slate coverings is simple and even novice craftsmen can do it.

The roof can be made from a flat one. and wave slate. Flat slate is recommended for roofs with a large slope.

But in any case, the geographical location of the region should be taken into account.

How to insulate a roof without removing slate: a simple method

Slate

- one of the most popular roofing materials, it has been used successfully for a long time and is not going to lose ground. Slate roofs are easy to insulate without removing the slate, but there are a few key points to be aware of.

Features of the roofing system for slate covering

How to make a plywood ceiling with your own hands

1. Rafter system. 2. Sheathing with a 60x60 mm block with a pitch of 750 mm. 3. Skate support board. 4. Frontal board. 5. Stop board for laying the first row of slate; after laying the slate it is dismantled

Slate does not accept movement in the substructure, so all the trusses are strengthened with each other by a common ridge beam, under which supports are mounted when the length of the slope is more than 10–12 m.

All wood used in the roofing system must be naturally dried within six months in a properly stacked pile. Minor holes that appear as a result of warping are directed into the attic. Careful culling is also necessary: lumber with defects is set aside and subsequently unraveled for lathing.

The sheathing is done with an unedged board with a clearance of 10–15 cm if it is planned to cover it with flat slate. For the wave format, a rare sheathing made of 60x60 mm timber, packed with a pitch of 45 to 60 cm depending on the number of waves and, accordingly, the size of the sheet, is better suited. After installing the sheathing, it is recommended to immediately nail the frontal and wind boards, along the edge of which the direction of the wave is set.

The presence of cross lathing is most important for slopes with a large area, where it is necessary to compensate for shrinkage and thermal expansion, avoiding overstress in the slate. In general, destruction of the coating most often occurs due to the use of low-quality or poorly dried wood.

Do-it-yourself roof insulation in a private house

Let's consider the process of insulating the roof of a house with your own hands in general terms. Detailed roof insulation technology is presented at the link.

First you need to install a counter-lattice to ensure air movement in the under-roof space. This is a very important point and should not be neglected.
The second step will be to strengthen the waterproofing on the counter-lattice. There are many types of waterproofing membranes or films; the use of one or another is dictated by the capabilities of the user.
Next, a layer of insulation - mineral wool or expanded polystyrene, cut exactly to the size of the spaces between the rafters. The insulation can be temporarily held between the boards due to its own elasticity, but for reliability you can fasten it with fishing line, for which you need to hammer nails into the rafters.
After strengthening the insulation, a layer of vapor barrier is applied. This is a film material that prevents the accumulation of condensation and wetting of the insulation. Glassine, polyethylene or polypropylene film are often used. The strips are attached to the rafters with a stapler and connected to each other with tape to achieve tightness.
The last step will be tying with sheet materials to secure the “pie” and protect it from mechanical stress. As you can see, insulating the roof from the inside with your own hands (photo of the process below) is quite simple and does not require any special knowledge from you.

Preparing surfaces for insulation

Before carrying out thermal insulation measures, you need to clearly know what kind of structure you will have to work with . Based on its technical characteristics, a work plan is determined. The following factors are taken into account:

geometry features (angle of inclination, width, length, etc.), shape and number of slopes;
type of roof covering;
type of rafter system;
main building material of the building;
availability of laid communications;
the roof extends beyond the main structure.

Preparing roof surfaces

It is worth correctly calculating the necessary materials and the approximate time for their installation. When the process is visually presented, everything is weighed and scheduled, then you can cope with absolutely any task. Whether it’s the roof of a rural house or a huge country villa, the algorithm of actions is similar. To properly insulate a roof, you need to properly prepare it:

carry out a thorough inspection of the rafters and sheathing - if damaged elements are found, they must be replaced;
treat wooden parts with varnish or antifungal solution;
check the integrity of communications laid in the under-roof space.

Communications under the insulation

Once the preliminary stage has been completed, you need to make sure that you have all the materials and tools necessary for insulation. If everything is in order, you can start working.

Main difficulties

Slate has a wavy shape and it will not be possible to lay the insulation close to its surface. This is one of the main problems, since creating a dense heat-insulating layer in this case will be difficult, especially when using fibrous insulating materials. It will be necessary to install a special system of cranial bars and sheathing so that the insulation has something to rest against during installation.

The second difficulty is waterproofing the heat-retaining material. The slate waves run along the entire plane of the roof and moist air easily enters them, which can render any fibrous insulation unusable - moisture can accumulate in them and the effectiveness of the material will decrease. Therefore, it is necessary to ensure high-quality waterproofing.

Previously, roofing felt was used as a water insulator, nailed directly to the roof sheathing before laying the slate. However, over time it very quickly becomes unusable and cannot serve as full protection against water. You will have to attach another layer of waterproofing materials to the rafters. It could even be a simple plastic film.

However, the question immediately arises of removing excess moisture from the insulating layer. It is necessary to secure the vapor barrier and waterproofing membrane in such a way that small ventilation channels are maintained between it and the roof, through which moist air will escape outside. Moreover, this must be done extremely carefully so as not to damage the protective film.

RECOMMENDATIONS FOR SOLVING THE PROBLEM OF CONDENSATION IN A COLD ATTIC

Based on the home inspection, the customer was given the following recommendations:

1. It is necessary to ensure good ventilation of the entire volume of the attic room with outside air. To do this, it is possible to use one of two schemes for organizing air flows in a cold attic:

Schemes for organizing cold attic ventilation

In the diagram: a) – attic ventilation through dormer windows; b) – attic ventilation through eaves and ridge vents.

The best option for attic ventilation is ventilation scheme “b” - through vents in the roof eaves and at the ridge. But, in the absence of the technical ability to organize such products, a fairly effective measure would be the implementation of scheme “a”, i.e. installation of dormer windows on four roof slopes on all sides of the horizon. And if the house had a simple gable roof, then it would be enough to install ventilation windows on two opposite gables of the roof.

Variants of dormer window shapes (in ventilation scheme “a”)

In Fig.: 1 - Gable; 2 - Single slope; 3 - Valmovoe; 4 - Arched; 5 - Triangular; 6 - Arched with a pediment in the plane of the facade.

Options for exhaust ducts in the ridge part of the roof (in ventilation scheme “b”)

In the figure: a) – ridge slot hood; b) – point exhaust using ridge aerators.

In any of the above options, the optimal area of the ventilation ducts should be 1/300 of the attic area, but not less than 1/500. Thus, for example, with an attic area of 120 sq.m., the area of the ventilation ducts through which outside air enters the attic should be in the range from 0.24 sq.m. (2400 sq.cm) to 0.4 sq.m. (4000 sq.cm).

2. It is necessary to ensure complete airtightness of the attic staircase hatch in order to prevent the penetration of warm, humid internal air from the premises of the house into the attic.

3. It is necessary to insulate the attic ladder hatch from the attic side in order to avoid freezing of the hatch and, as a result, condensation on its inner surface facing the premises of the house.

The insulation of the hatch can be carried out according to the design of an exit to the attic in the form of a thermally insulated cabin with a door into the attic volume, or according to the design of a thermally insulated box with a horizontal lid.

4. It is necessary to clear the attic space of construction debris and material residues to ensure maximum circulation of ventilation air throughout the entire volume of the attic and avoid stagnant zones.

The results of a similar inspection of a cold attic, carried out by SЌРєСЃРїРµСЂС‚Р°РјРё РђРєР°РґРѕРјРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРёРІР°С‚‚ РІ С…РѕР»РѕРґРЅРѕР ј S‡РµСЂРґР°РєРµ».

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Choice of insulation

Having dealt with the protection of heat-retaining material, it is necessary to move on to one of the most important issues - the choice of insulation. It must be selected in accordance with the requirements that are placed on it. At the same time, in different cases these will be different requirements.

For houses where residence is not permanent, a thin layer of material is sufficient - from 50 millimeters. It will retain heat while the house is being heated and will allow it to escape fairly quickly after the heaters are turned off or the furnace goes out.
Permanent housing requires a different approach - you need to retain heat as efficiently as possible and the insulation layer should be at least 100 millimeters.

These data are true for a layer of mineral wool - the most popular and popular insulation. However, there are other options for insulating materials. For example - polystyrene foam. It is lightweight, easy to install and retains heat well. But, it also has enough disadvantages that will outweigh the advantages in the form of cheapness and lightness. This is a very flammable material that releases harmful substances when melting and burning. In addition, many people are allergic to the smell of polystyrene foam. So, it is suitable for technical structures, but it is better not to use it for housing.

Spray polyurethane foam can be an ideal solution for slate roofs. This is essentially a sprayed insulation that covers the entire treated surface with a dense layer, without cracks or gaps. When using it, it will only be necessary to ensure that there are no through cracks and holes in the roof and on the side of the gables. Its only drawback is the lack of air exchange between the external environment and the treated room. You'll have to think about good ventilation.

Another option for how to insulate a slate roof from the inside would be to use bulk insulation materials such as expanded clay, which are laid on the side of the ceiling that is external to the premises. This solution will not make the attic warm, but the insulation of living spaces will be very effective. The most modern material in this category will be ecowool, which can simply be scattered over the surface of the ceiling and covered from the outside with a waterproofing film.

How to choose roof insulation

The scope of work requires the use of a large amount of thermal insulation materials. This causes high demand for rolled roof insulation, which has a low price. But does this material always meet the requirements of heating engineers and installers? Let's consider the main criteria for choosing a heat insulator, which will help you buy the best products on the market.

Thermal insulation

Thermal conductivity coefficient is the main selection parameter. The lower the value, the better the heat transfer resistance ability. Choosing products with low thermal conductivity not only ensures the maximum level of comfort, but also allows you to reduce, if necessary, the thickness of the roofing “pie”. A high level of thermal insulation is provided by a layer of insulation made of stone wool or mineral fiber 150-200 mm thick. The exact values depend on the climatic characteristics of the region and are calculated by heating engineers.

Environmental friendliness

Phenol-formaldehyde and acrylic resins are used to bind mineral fibers into a board. The fewer of these substances in the composition, the safer the material is for human health. Insulation materials made from fibers obtained as a result of molten rocks are environmentally friendly products. Materials made from fiberglass have an increased emission of dust, which causes skin irritation. It is better not to use this product.

Insulation materials based on sawdust and other organic substances are very popular. These products do not cause allergic reactions or skin irritations, but have a significant drawback - a low level of fire safety.

Durability

The design features of the flat roof and the slopes of the attic floor make planned repairs difficult. To replace the heat insulator, it is necessary to remove the finishing materials and open the leveling layer of plasterboard. This makes repairs expensive. To ensure that the insulation does not have to be changed every 10-15 years, it is necessary to choose the right products.

The material for pitched roofs must be elastic, not cake under its own weight, and not accumulate moisture in its structure. These factors ensure durability. The best manufacturers produce stone wool and extruded polystyrene foam with a service life of 50-100 years.

Hygroscopicity

The ability to absorb water is one of the main criteria that has a negative impact on thermal performance. If the fibers well adsorb drops of water that are present in the water vapor released during life, then within 1-2 years the material will increase its density, and the thermal conductivity coefficient will increase by 2-3 times.

The attic floor will become cold in winter and heating costs will increase. Products with low hygroscopicity have an advantage. To reduce it, fibers are treated with hydrophobic impregnations. The cells of extruded polystyrene foam, unlike conventional polystyrene foam, have a closed structure. This allows for minimal hygroscopicity throughout the entire service life.

Fire safety

Fireplace chimneys and heating boiler chimneys lead to the roof of the building. An accidental spark can cause a fire. The materials used in the construction of the roof are subject to special fire resistance requirements. Wooden rafters are treated with fire-retardant impregnations, and when insulating, thermal insulation is used that meets the strict requirements of fire safety rules. The best characteristics are found in slabs made of basalt fiber, which are used as a fire barrier when protecting load-bearing structures.

Insulation of a roof that does not have counter-lattens and waterproofing

To secure the waterproofing membrane from the inside (from the attic side), you need two bars on each side of the rafter leg and one in the middle between the rafters.

The first pair of bars is attached to the rafters close to the roofing, the central bar is attached parallel to them to the sheathing - they are responsible for creating a ventilation gap between the membrane and the roof. It is necessary to ensure the flow of air into this space through the eaves overhang.

The thickness of the block can be 3-5 cm and should be sufficient to “hold” the fasteners - these are just spacer strips. And the width of the bar is chosen based on the requirements for the size of the air gap, so this size should not be less than 4 cm.

After installing the spacer strips, a waterproofing membrane is laid between the rafters. In a standard situation, it is laid over the rafters from the bottom up in horizontal strips with overlapping joints; here the installation is carried out “vertically” - one strip between each pair of rafters.

Why can't you insulate your roof?

Having told how to properly insulate a roof and with what, we can already remind you that it cannot be insulated. Forbidden, under no circumstances.

“This is news to me!” - write puzzled homeowners, when a consultant of our portal with the nickname Matilda once again patiently explains this “once again, for those who understand.”

The roof must remain cold.

Everyone knows that the roofs of low-rise buildings are insulated throughout the vast expanse of Russia, from Kaliningrad to Vladivostok, and that natural materials were used as thermal insulation in the homes of our ancestors.

But no, this is a mistake.

MatildaFORUMHOUSE Consultant

The roof must remain cold. Insulate the room. The phrase “insulate the roof” means laying insulation between the rafters, as close as possible to the roof covering. This is done to maximize the volume of the room.

And the roofing itself must remain cold! This means ventilation is necessary.

MatildaFORUMHOUSE Consultant

The air enters at the eaves into the cracks of the filing and exits at the ridge into special valves. In the place where the floor, walls and roof meet, make sure that there is a gap of at least 5 cm between the roof and the insulation for air passage.

After converting an attic into a warm attic, the humidity in the room can increase significantly. The air temperature in an unheated attic is almost the same as outside, there are no problems with condensation, so it is enough to insulate the ceiling well. In winter, it is much warmer in an insulated attic than outside, and most importantly, the air is more humid; moisture rises upward along with warm air, comes into contact with the colder surface of the roof - condensation forms. And this is not so bad - if the insulation layer is not laid well enough, then moisture penetrates into the roof structural elements, and they will not last long.

For most homeowners, this is “sudden”:

Urfene DjusForumHouse Member

They will wake up when the finish begins to get wet, and this will already have consequences.

Problems with condensation can also occur:

Due to cracks or other defects in the roof structure (it is recommended to inspect them before insulation and, if possible, replace them);
Due to poor-quality vapor barrier, or the absence of a vapor barrier layer in the roof pie;
Due to problems with the attic ventilation system. We made repairs, installed plastic windows, moved or blocked ventilation holes, and voila - wet spots on the finish.

That’s why professional roofers attach such importance to vapor barriers, and on the roof side, the thermal insulation material is protected with a layer of waterproofing - this results in double protection. But even that is not enough.

Urfene DjusForumHouse Member

You will not prevent steam from penetrating into the cake one hundred percent, and humidification will occur at the dew point.

Without good ventilation, problems will still appear - the roofing gurus of our portal always insist that in a warm roof pie there are gaps for air circulation on both sides.

KabykiFORUMHOUSE Member

Finishing, gap 2 - 3cm, vapor barrier, insulation, vapor-permeable membrane, ventilation gap 50mm, step lathing, roofing.

And so that air can move freely through these gaps and remove moisture from the heat-insulating material, vents are made in the overhang and upper part of the roof, or the insulation is mounted up to the crossbars, leaving a cold triangle. This option is considered better than insulation up to the ridge, but only if the cold triangle is ventilated.

raf2603FORUMHOUSE Member

The cold triangle must be ventilated; for this purpose, ventilation grilles are made on the gables, as well as GI cuts on the ridge (but to prevent snow from sweeping under the ridge, you need to install an aero element or seal under the ridge).

Insulation of a roof that does not have a counter-lattice, but has a vapor barrier

The difference between this version of the roofing pie device is that if the roof leaks, water will not get onto the insulation. In addition, if the vapor barrier has an anti-condensation surface, then it will “bind” part of the condensate that forms when the atmospheric air cools.

But this condensation, just like excess moisture in the insulation, must be ventilated from the under-roof space. And for this you need a conro-lattice with a vertical ventilation gap.

In this case, the waterproofing membrane can be attached a little easier than in the previous case:

Between each pair of rafters, parallel to them, three or four slats are placed (depending on the distance between the rafter legs). The thickness of the rail is chosen equal to the size of the air gap (usually 4-5 cm).
A waterproofing membrane is laid between the rafters. It can be laid either in one strip vertically or in pieces of panels horizontally with the top panel overlapping the bottom by 15-20 cm (installation must be done from top to bottom).
The waterproofing membrane is stapled to each batten and along the rafter legs.

Thermal insulation material and vapor barrier are laid using standard technology.

Waterproofing pitched roof

In addition to functional requirements, the selection of a waterproof coating for a pitched roof includes equally important aesthetic ones. After all, in many ways it is the roof of the house that is responsible for the perception of its exterior.

The assembly of a pitched roof pie can be carried out according to two main schemes - with or without insulation. Each option uses a set of materials that have some variability depending on the specific situation.

Layers of a pitched roof pie

Waterproofing materials for pitched roofs

Insulated and ventilated non-insulated pitched roofs can have the same external protective and decorative coatings, determined only by the personal preferences of the property owner and the price he is willing to pay for them:

sheet metal tiles, asbestos-cement slate, cellulose-bitumen slate (Ondulin type), corrugated sheets, seam elements;
piece tiles - ceramic, cement-sand, slate, composite, bitumen (such as soft roofing Shinglas or Finnish soft roofing Katepal Ruflex, Icopa or Kerabit).

Soft roof made of butumen tiles The listed coatings do an excellent job of providing basic waterproofing for the building from precipitation. However, according to modern construction standards, they need substrates made of waterproofing films (polyethylene, polypropylene) or any rolled bitumen, bitumen-polymer materials. In non-insulated roof structures, the rolls are rolled out in strips across the rafters, starting from the bottom of the pitched plane. Each subsequent strip covers the previous one by at least 15 cm. The additional hydrobarrier being formed is pressed against the rafters with counter-battens, onto which a sheathing or solid flooring (made of boards, plywood, OSB) is already attached, and then a protective and decorative coating.

Thus, a ventilated gap is formed in the under-roof space, communicating at the top point with the ridge aerator. Through this ventilated channel, accumulations of condensate and small amounts of precipitation blown through the leaks between the coating elements are freely removed. Metal roofs especially need such under-roof ventilation, under which condensation forms excessively during temperature fluctuations. Therefore, an additional waterproofing carpet must be installed under metal tiles, corrugated sheets or seam sheets.

On an insulated pitched roof, the arrangement of the under-roof carpet is carried out in a similar way, although its range of tasks may be slightly different. In addition to protecting the insulation and rafter structure from wind, precipitation and condensation, the auxiliary waterproofing layer should not prevent steam from escaping from the thermal barrier. For this:

if a vapor-permeable windproof membrane is used (such as Izospan AQ proff, Izospan AM, Izospan AS), then it is laid directly on the insulation along the rafter legs;
if a hydrobarrier with low vapor permeability is used (such as PE film or Izospan DM), then another rail is drilled under it along the rafters to create a lower ventilation gap.

Izospan AQ proff is a professional three-layer superdiffusion hydro-windproof vapor-permeable membrane

Insulation of the U-shaped attic contour

If the roof is high and the area of the house is large, then the attic can be equipped without sloping walls - with a U-shaped contour, the thermal insulation of which will not come into contact with the roof.

In this case, behind the contour of the attic there will be an ordinary cold attic with its own ventilation through the eaves and ridge vents. In essence, this is a technology for insulating a frame house, but inside the attic.

Insulating the attic ceiling:

Boards or slats of the rough ceiling are hemmed to the top ties, which act as ceiling beams.
A vapor barrier is installed on the side of the room. The strips are laid overlapping and all joints are glued.
On the “attic” side of the attic, insulation is laid between the tie beams (if necessary, in two layers).
A waterproofing membrane is spread over the insulation. It is required if it is not included in the roofing pie. If the roof has waterproofing, but the mineral wool mats are not laminated, then ordinary fiberglass can be laid on them as a wind barrier.
On the inside, a counter-lattice is attached over the vapor barrier. It is needed to ensure that there is an air gap necessary for the functioning of a vapor barrier with an anti-condensation or reflective surface.

Insulation of attic walls:

A waterproofing windproof membrane is attached to the outside of the posts.
If the contour of the attic on the roof side is sheathed with plywood or OSB, counter-lattice bars are nailed to the posts on top of the waterproofing.
Thermal insulation is laid between the racks.
A vapor barrier is laid in a continuous layer on the inside of the racks. Tape the junction with the vapor barrier of the ceiling and floor.
Install the sheathing for the interior lining.

If none of the options suits you, then the roof can be dismantled, and waterproofing and insulation can be carried out using standard technology.

How to insulate a roof. Step-by-step instruction

When insulating between rafters, it is important that the thermal insulation layer is continuous, without gaps in the corners, near pipes and windows. The slightest gap leads to the formation of a cold bridge. If some part of the structure is less insulated, then the temperature there is lower, and - hello, condensation.

The roof insulation pie is the basis of the basics; you cannot swap layers in it or skip any of them. How to insulate a roof from the inside, from bottom to top:

Internal cladding (lining, OSB, etc.);
Ventilation gap;
Vapor barrier;
The frame on which the insulation is mounted;
Vapor-permeable hydro-wind protection membrane;
Counter-lattice made of a bar of at least 45 mm (usually 50);
Lathing;
Roofing covering.

You should step by step consider all the layers of the roof insulation cake of a private house and the installation technology.

Inspection of structures. If the house has been standing for many years with a cold attic, and it has been decided to convert it into an attic (and this increases the living space of the house by 35-40%), then the first thing you need to do is to revise the structure. Was the roof installed well and correctly? How well are the rafters and floor beams preserved? If any parts of the structure become unusable, they are replaced and treated with fire and bioprotection. Then they measure the thickness of the rafters and the distance between them, and cut the insulation so that its width is 1.5-2 cm greater than the distance between the rafters. This way the insulation will fit tightly, without gaps. But in houses, especially old ones, there may be the most unexpected distances between the rafters, and then you have to lay out a mosaic from insulation and waterproofing film, as a user of our portal with the nickname 214457 did. The distance between the rafters on the roof of his house is 1300mm, and the width of the vapor barrier is 1600mm.

Installation of hydro-wind protection membrane. At this stage of roof insulation there are a number of subtleties on which the result of insulation will depend. Usually waterproofing is done when the roof is covered, but if the roof of a private house, installed before historical materialism, is insulated, there may not be any waterproofing. It is better to buy a modern super-diffusion membrane - it will not let water into the room, but will release steam from it.

The film is attached to the rafters without tension, with a sag of 20 mm. It will be ideal if the distance between the rafters does not exceed 1.2 m. Why you should not stretch the waterproofing: it will shrink from the cold, and if you do not leave sagging, it will tear.

The waterproofing film is fastened either with a construction stapler or with galvanized nails, always with a wide head, and rolled out horizontally from the eaves to the ridge, always leaving an overlap. And here it is important that the size of the overlap matches the slope of the roof.

The slope exceeds 31 degrees - overlap 10 cm;
The slope is 22-30 degrees - overlap 15 cm;
Slope less than 21 degrees - overlap of 20 cm.

It will be great if the overlaps occur on the wooden parts of the structures: rafters, or, if they are needed, spacer bars, etc. Overlapping areas are isolated with adhesive tape.

Also: it is very important not to mix it up and not to place the film with the wrong side up when using it. Homeowners often make this mistake, although the film always indicates which side is the outside and which is the front.

Laying thermal insulation. Then the thermal insulation material, cut to size, is tightly laid between the rafters, pressing against the waterproofing and shifting each subsequent layer to the side relative to the previous one so that cold bridges do not arise.

The insulation is cut strictly 2 - 3 centimeters wider than the width of the rafter span: it should fit tightly, but not bend over.

KabykiFORUMHOUSE Member

It is better to insulate in several layers with offset. Three times 50 is better than one time 150.

The slabs are secured using thin slats or lines that are pulled between the rafters.

Installation of vapor barrier. It is best to install the vapor barrier as recommended by the film manufacturer.

The vapor barrier must not come into contact with the insulation!

The first strip of vapor barrier is at the ridge, and the subsequent strips are closer to the eaves, with an overlap, and are secured in the same way as waterproofing, only they are tensioned, there should be no sagging. The gluing areas are reinforced with a pressure strip, especially if the roof slope is less than 30°.

When installing a vapor barrier, it is extremely important to ensure a tight connection to the surfaces. At junctions with walls inside the attic, chimney pipes and other complex surfaces, glue must be used; it needs to be made “for centuries”, and adhesive tapes and adhesive tapes will not be enough for this. The staples from the stapler are additionally taped.

Installation of counter bars. Counter beams are nailed along the rafters to provide a longitudinal ventilation gap. Counter bars must be at least 50 mm thick. Step lathing is nailed onto them .

An insulation pie is possible with one ventilation layer, the top one, and the vapor barrier is always adjacent to the insulation.

Nowadays, more and more often, the roof is thermally insulated directly during installation: such insulation is of higher quality.

KrovellForumhose Member

If only because otherwise there will be no possibility of high-quality insulation behind the Mauerlat. And this is a very important node!

The insulation pie in this case is performed in reverse:

Install a vapor barrier on the lower surfaces of the rafters, starting from their base to the ridge, with overlaps at the joints, gluing the joints with construction tape;
From below, the vapor barrier film is nailed across the rafters with bars with a cross-section of 30x40 mm in increments of 30-40 cm. The finishing material will be attached to them from below, and this structure will hold the thermal insulation.
Insulation boards are placed on the waterproofing between the rafters; the surface of the boards should be flush with the top edge of the rafters.
Vapor-permeable waterproofing is placed on the slabs with an overlap of 15 cm.
The next layer is the sheathing, on which the roofing material is already placed.

Which side should you put the slate on?

The surface of the slate sheet is different on both sides. On one side it is more corrugated, on the other side it is smooth. When laying slate on a roof, the smooth side should be on top.

This is necessary so that snow can easily roll off the roof in winter and not create blockages, which can lead to water leaking through the overlaps.

It is necessary to calculate the number of sheets of slate required for covering, taking into account the overlap, both horizontally and vertically.

You need to start laying slate on the side opposite to the prevailing winds in the region.

During normal installation, on each sheet of slate, except for the outer ones, two corners located diagonally are cut off in order to reduce the thickness of the overlap.

When laying offset, when the next horizontal row is shifted by half the width of the slate sheet, this is not necessary.

Minvata

This type of insulation is considered the most common among modern builders. Many professionals recommend using this particular material as the basis for an insulating layer.

Since the composition of such materials may differ, everyone will be able to choose the right product for themselves, taking into account the necessary quality characteristics. When purchasing mineral insulation, you will have to ask the seller for a safety certificate.

Useful tips

If the attic appears to be a large and cold room, you can use various types of insulation, after which you can live in this room. Thermal insulation material can be laid both during the construction of the roof and after that. If the roof is already covered with slate or other material, then the work is done from the inside, which changes the arrangement of the layers during the installation of insulation.

When working with glass wool, it is necessary to use protective equipment to prevent glass particles from getting into your eyes or nose. The choice of modern materials is not always the most acceptable, if only because of their high cost.

The correct procedure for laying all layers will allow anyone, even a non-professional, to insulate a room.

What to choose as insulation

The classic material is mineral wool,

suitable in most cases. It is inconvenient for transportation, as it stains the car interior, can generate dust and cause coughing. However, there are other materials, such as polystyrene foam. It is cheap, easy to transport and install. It is very light, so it is easy to work with in the attic, it is easy to lift such panels up and fasten them.

Expanded polystyrene panels can be transported on the roof or trunk of a car. There are also disadvantages: the material causes allergies, so it is not suitable for everyone. In case of fire, it releases toxic substances and is itself very flammable and flammable. It is usually used for offices and industrial premises, but is not recommended for apartments.

You can also find other types of insulation on sale, which are more expensive, but have their own advantages.

Recently, an advanced method has appeared - sprayed polyurethane foam

. This is a sprayable material that fills all the cracks and reliably seals the roof. The disadvantage is that it interferes with ventilation, and the owners of the premises will have to think about how to ventilate the room and remove moisture from it.

Selection of tools

If you ask a professional roofer what tools you need to have to insulate the roof, he will probably answer that a knife, a hammer, a clear head and skillful hands. Essentially, this is the case, but there are subtleties and secrets that not everyone wants to divulge.

Roofing tools

The most important detail and, accordingly, the trick is choosing a knife . If you take a regular mounting knife, you will be able to work, but throughout the entire time you will suffer from unevenly cutting off pieces of insulation. Such a construction tool has a blade that is too short and is unable to cut through a thick layer of heat-insulating material. In addition to all this, a standard knife will quickly become dull on polystyrene foam or mineral wool.

If you don’t have a knife, then you can use improvised means for cutting - a hacksaw for wood or a wide kitchen bread cleaver with a lumpy sharpening.

The ideal option would be to purchase a special professional long knife . It is made taking into account the requirements placed on it - made of carbon steel with a length of 35 cm and a comfortable handle made of high-quality plastic.

Professional knife

In addition to a good cutting tool, you will definitely need a hammer, a screwdriver, self-tapping screws of different lengths, a long strong cord, reliable protective clothing, glasses to preserve your vision and a respirator.

It would also be a good idea to listen to the following recommendations:

the place where thermal insulation materials are to be cut must be well ventilated;
carefully protect your hands, head area and, especially, the respiratory tract with your eyes - they are most susceptible to damage from flying fibers;
after work, immediately take a shower, thoroughly washing your hands, face and other areas of the skin;
before cutting, make sure that the size is correct - the pieces should fit freely between the rafters, without falling out or being squeezed;
It is advisable to cut mineral wool across the fibers - this minimizes the release of flying particles.

Cutting mineral wool

Physical factors: impact

Any house that is used for housing must meet certain requirements to make living in it cozy and comfortable. It is important to lay the foundation correctly so that the house does not shrink or crack, insulate it and build a roof. The choice of covering is very important because it determines the weight that is applied to the house, the time it takes to complete the covering work and the cost. In addition to all this, it is necessary to take care of insulating the inside of the roof so that the structure of the house remains as reliable as possible and the residents feel comfortable at any time of the year.

In different climatic conditions, buildings are affected by various factors.

Our latitudes will be characterized by:

precipitation in the form of rain;
snow, cereals and similar phenomena;
hail;
roof icing;
active sun;
strong wind.

To withstand all these negative factors, the roof must be covered with sufficiently dense materials that can reliably protect the house for many years.

A private house is a structure that consists of a main floor and an attic. If the roof is not insulated, then up to 15% of the heat from the room escapes through the ceiling in cold weather, which makes it necessary to intensively heat the rooms. In addition, having an insulated attic, this space can, if desired, be made residential and used as rooms for a specific purpose. For a large family this is an ideal option.

How does condensation form, the reasons for its accumulation under the roof arch?

Condensation is water, but how does it get to the ceiling and roof elements? To understand this you need an understanding of thermophysical processes.

There is always moisture in the air in the home in the form of steam. So water can be in a warm air mass. However, when a cold object is encountered in the path of the air flow, all the moisture falls into drops, that is, condensation forms.

Since warm air masses rush upward, and there they are met by a cold roofing structure, all the condensation goes to the roof. An uninsulated roof is a prime candidate for getting wet and should be insulated immediately. But the worst thing is not a wet roof, but the consequences when the metal elements of the roof begin to corrode, and the wooden elements become damp and lose their strength.

Processes inside

In order to properly insulate a private house and make the roof a full-fledged protective mechanism for both the main room and the attic, you need to be able to choose the right material for insulation. Usually the selection is based on the physical processes occurring inside, under the roof.

There are several of the most important ones.

Heat exchange , which occurs due to different temperatures in the house and outside it. If the roof is not insulated, then some of the heat escapes through the roof, and the insulation prevents this process and maintains optimal temperature in the room.
Moisture exchange , which occurs from the person himself, his breath, evaporation from body temperature to the cooking processes, when vapor rises to the ceiling, carrying particles of moisture that are removed through the roof. If the roof is insulated, the humidity level remains optimal, and unnecessary odors can be removed using ventilation.

The main mistakes when insulating a roof

Actions that can negate all your work and expenses:

incorrect selection of the thickness of the thermal insulation material can lead to wasting extra money or the lack of the desired result;
ignoring ventilation will create excess moisture and condensation in the room, which will lead to damage to the coating and rafter system;
By neglecting the steam and water barrier, you can get a negative result in the form of condensing moisture, which will be absorbed into the heat insulator, violating its properties.

Almost all private households located in most regions of the country roof insulation from the inside Therefore, such events should not be postponed “for later”. It is better to carry out thermal insulation at the construction stage of the building. Properly organized roof insulation is the key to comfortable living in the house and a noticeable reduction in energy costs.

Necessity or whim?

A private home often has a pitched roof that creates an attic space on top of the main living floor. If there is no insulation, then living in such conditions will be very uncomfortable due to the lack of heat during the cold season. If the attic is designed as a residential floor - the same attic, then the insulation process must be mandatory.

Any roofing material cannot protect as much as polystyrene foam, mineral wool or another type of coating. In addition to the insulation itself, it is important to use a vapor barrier film that can cope with various types of fumes.

If you ignore the installation of an insulating coating, then in addition to the cold in the house, very soon problems will begin with the roof rafter system , which will rot and there will be a risk of collapse. The same effect can be observed with incorrect installation technology or inaccurate choice of insulation. If you choose the wrong thickness of the insulation, then instead of protection it will have the opposite effect. Under normal conditions, when there is a difference in temperature, protection is provided against condensation and heat loss, which makes it possible to feel comfortable in any weather.

If the thickness is compromised and thin insulation is selected, then an excessively large amount of condensation will form on it, which will contribute to rapid rotting of the rafters and disruption of the microclimate of the room.

Failure to comply with the standards is dangerous for both health and safety , since the roof structure may collapse. The choice of material that needs to be insulated depends on a wide variety of factors that are important to consider in order to be able to independently install what is needed. If difficulties arise with the choice of insulation or its installation, it is better to contact professionals and receive comprehensive advice and assistance in installation.

Mineral wool

This is one of the most popular materials for roof insulation. The thermal conductivity coefficient of mineral wool ranges from 0.045 to 0.030 W/(m*K).

To meet the technical requirements for the roof structure, the insulation thickness must be between 20 and 25 cm.

The first layer of such insulation is placed between the rafters, making sure that the entire space is completely filled, additionally connecting the boards with tape.
A small (3-4 cm) gap is left between the layer of wool and the roof boards so that the roof can “breathe” (if a suitable membrane is not used).
The second layer of insulation should be laid under the rafters to avoid thermal bridges.

Mineral wool is attached to the roof using galvanized steel profiles, which are connected to the rafters using special hangers.

Roof “pie”: what is it like?

A properly constructed roof involves a large number of layers of different materials that are layered on top of each other, resembling a pie - hence the name. The basis of the construction “pie” is the rafters, on which all other layers are already being laid.

To correctly lay out all the layers, it is important to know their correct sequence, which looks like this:

Roof.
The lathing on which the finishing materials will be installed. It can be laid completely or with gaps.
A counter-lattice in the form of bars, which serves to ventilate the space under the roof itself.
Film for waterproofing.
Materials for thermal insulation.
A layer of vapor barrier material.
Creating a sheathing where insulating materials and internal lining are mounted.
Material for internal lining.

If you lay the “pie” correctly, you can avoid heat loss from the living space during the cold season, and it will also help prevent the space from overheating in extreme heat. The waterproofing layer will help protect the insulation from moisture coming from outside, and the vapor barrier layer will protect against various types of fumes.

A pitched roof is a fairly common type , so it will not be difficult to select all the necessary materials for it. The positive aspect of high attics is the convenience of insulating them and the ability to create a full-fledged living space.

Without additional work, it will be extremely unpleasant to be in it - it is very cold in winter, and too hot in summer.

A way to insulate the roof of a house from the inside to avoid condensation

It is important to create comfortable conditions at home. To prevent excess heat from escaping into the street. For thermal insulation of the roof, mineral wool or basalt wool is most often chosen. These materials allow evaporation to pass through and reduce humidity in the room.

But mineral wool is afraid of moisture. Therefore, you need to protect it with a waterproofing film.

The film must be laid with sagging. Special glue the joints. with tape. The rafters must be dry when working. The mini-plates must fit snugly against the rafters.

Mineral wool slabs come after waterproofing and are placed closely between the rafters. It is necessary that there are no cracks or bumps. The material holds firmly without fastening. The width of the insulation should be 1 cm greater than the distance between the rafters.

A vapor barrier is laid on top. The film must be glued with an allowance for the walls. The smooth surface of the film should be in contact with the mineral wool.

Requirements for materials and their functions

To carry out quality work, it is necessary to choose the right materials. It will depend on them how accurately it will be possible to create comfortable living conditions and secure the roof supports. The choice will depend on the region where the building is located, its size, purpose, as well as the funds available to purchase materials.

There are four main methods of insulation.

Using mineral wool , which is the most commonly used material due to its properties. It is best to purchase the basalt variety. It is advisable to obtain a quality certificate from the store in order to know for sure that the products are safe and meet all norms and standards. There are varieties that are lighter in weight; they are suitable for working in conditions of independent insulation of the room. The positive qualities of cotton wool can be considered non-flammable composition and moisture repellence, which corresponds to the main task of this layer. In addition, rodents do not like it, which means you don’t have to worry about someone getting in the house, especially on the roof.

Among the disadvantages, one can note the rather high cost, but it is fully compensated by the positive aspects.

Use of glass wool. Some time ago, this material was considered the main one for roof insulation, but due to some dangerous properties, safer analogues were soon found. The thermal insulation of glass wool is quite good, and the efficiency is very high. When working with such material, it is very important to follow all safety rules, namely, use a protective suit, gloves, and goggles. It is important to close your nasopharynx and eyes to prevent pieces of glass dust from getting into them.

People with allergies will not be able to live in such a house, so you need to be able to choose the right type of internal insulation coating.

Polymer roof insulation consists of special tiles made of polystyrene foam and expanded polystyrene. They have both advantages and disadvantages. This is an inexpensive option, so anyone can afford it, but if you look at the disadvantages, you should think carefully about purchasing such insulation. These materials are very flammable, and when burned they produce a large amount of smoke, which is very dangerous to humans.

Usually this type is used when other options cannot be used.

Insulation with expanded clay. This material is very often used for floor insulation and has good thermal insulation properties, but it is very difficult to use for roofs due to heavy installation. Usually only experienced workers can handle it to make internal insulation of the ceiling in the house.

If we consider alternative options, among them are polyurethane foam, which can be used in two states - in the form of slabs and foam. It is advisable not to take slabs for arranging the ceiling, because working with them is inconvenient and they are very expensive. At the same time, liquid or foamed polyurethane is easy to apply and has a number of advantages. With its help, you can fill voids of any shape and size; cracks and opening lines are very well clogged. If other materials need to be cut and achieved maximum fit, then in this case the foam will fall on its own, the main thing is to distribute it correctly and evenly.

It is very convenient to use foam for roofing made of slate or broken structures when there are many differences on the roof and the frame has significant differences. Another significant advantage is the independence from hydro- and thermal insulation, which are not needed for polyurethane foam. In addition, the material has excellent flammability resistance, which ensures home safety.

Do you need steam and moisture insulation under slate on a gable roof?

How and what to make balcony ceilings from?

In what cases is it necessary to lay a steam and moisture-proof layer on the roof? Is it needed if the roof is made of asbestos-cement slate?

Regardless of the final roofing covering, both vapor insulation and waterproofing are needed, provided that the roof is insulated.

Vapor insulation is laid from the room, waterproofing is placed on top of the insulation, and slate is finished at the finish.

If the attic is a living space (attic), then the whole “pie” is needed.

Steam and waterproofing under asbestos-cement slate is not necessary. This thing is installed only under metal tiles or profiles. It is on this material that condensation accumulates, from which it is necessary to protect and drain it into the drain. In addition, if the thermal insulation of the ceiling is well done, then there is no condensation even under the metal - this has been tested in our kitchen - the metal has been standing without steam and waterproofing for 6 years and is still like new.

Waterproofing is needed if the material from which the roof is made is susceptible to destruction from moisture escaping from the house. That is, if the roof is covered with metal siding or metal tiles, then it is necessary to lay waterproofing. And if you cover the roof with slate, that is, a material that does not corrode, waterproofing is not needed. After all, no matter how tightly you lay the thermal insulation on the roof, it still breathes. Wood passes moisture through itself with heat; even brick is capable of conducting moisture through itself. So do not neglect steam and moisture insulation in those places where it is necessary.

It is advisable to install a vapor barrier under any roof covering; the fact that they did not use this film before only because it did not exist, but only installed it does not mean that a better and alternative material has not appeared now. In general, you look at the money, if you have money, install a vapor barrier and waterproofing, do it according to the latest architectural standards and developments, if you have no money, do as your conscience allows you, which will live with you with any roof, be it with a vapor barrier, with roofing felt or without anything!

In a house with 40 years of experience, the roof is pitched and under the slate there is roofing felt on the wooden covering. In this condition, even if snow blows under the slate in winter, the moisture will still not get into the attic space, which is used for storing grain feed stocks, wheat, corn, and seeds. On the attic side of the ceiling, glass wool is laid and covered with clay mortar. The ceiling is quite warm and does not allow cold to pass through and does not condense moisture.

I live in a private house, five years ago I covered the roof (it was 4 pitched, converted it to 2 pitched) with a metal profile, and before that it was made of asbestos-cement slate, it stood for more than 50 years, without any steam or water insulation, I didn’t use insulation either. laid it directly on the sheathing. The roof does not leak and I don’t know why steam-water insulation is needed. The attic floor was covered with a laminate backing (5 mm thick), polystyrene foam (100 mm thick) was used for insulation, and the joints were foamed with polyurethane foam. The ceiling in the house is not damp, there is no heat leakage (checked with a thermal imager). They say that polystyrene foam breeds mice, but in five years there have not been mice. temperatures vary - Novosibirsk region.

Thermal insulation for the roof: how to save yourself not only from heat loss, but also from excess heat

The official interpretation of the concept of “roof” states that it is the top element of the covering, “limiting the passage of the most intense heat flow.”
But the roof covering itself, whatever it may be, is intended mainly only to protect the under-roof space from precipitation, but not from cold or heat. After all, the times are already in the distant past when roofing also served as insulation - straw, thick clay tiles, wooden slats and reeds. But today's corrugated sheets, soft roofs and slate cope only with the first task, but not with the second.

So what to do, and how to stop almost 30% of home heat loss through the upper structure of the building, and in winter protect yourself from the same metal tiles that are hot from the scorching sun? There is a solution - high-quality thermal insulation for the roof!

Slate roof base

The supporting structure of a gable roof is sloping rafters, on top of which a sheathing of beams or boards is nailed. For small buildings, about 4-5 meters wide, the roof will consist of paired rafters with a tie between them. For larger sizes, you will need a central stand.

A meter roof height is quite enough for an ordinary garage 4 meters wide. We make the rafters from 50x100 mm timber. The pitch of the rafters is about a meter.

As lathing, we use unedged boards 25 mm thick. It is cheaper, and smooth edges are not needed for the sheathing. First, be sure to remove any remaining bark from it, otherwise the board can quickly be damaged by insects - wood borers.

To save money, we do not lay the boards completely, but at some distance (the builders say “with gaps”). For reliability, we make the gaps equal to the width of the boards.

The rafters and the tie between them are connected with screws or nails. We make the tightening from the same board as the sheathing. To simplify the design, we form the roof overhangs with rafter outlets.

The lower part of the rafter rests on a longitudinally laid beam - Mauerlat. We fasten the Mauerlat itself either with wire placed in the walls at the stage of laying them, or with anchors to a ready-made structure.

What else to consider

Mineral wool should not be pressed against the foil, even if it may come into contact with it. This can have negative consequences.

In areas where such padding may cause swelling, there is a risk of damage to the foil underneath the covering of easily heated materials (such as metal shingles). Then all your efforts will be wasted, and you will have to insulate the attic from scratch.

Wave slate: varieties and sizes

Several types of slate are in greatest demand among developers. Moreover, each variety differs in size and number of waves. As a rule, a sheet can have 5-8 waves. However, for private buildings, sheets of 7-8 waves are most often used.

Dimensional characteristics of eight-wave slate:

width is 1130 mm;
length is 1750 mm;
thickness is 5.8 mm;
The weight of the sheet is 26 kg.

The high consumer demand for this type of roofing material is easy to explain. Slate is usually laid with an overlap. The amount of overlap is usually 1-2 waves. As a result, if you cover the roof with 8-wave sheets, you can significantly increase their usable area.

Installation of slate sheets: procedure and technology of work

In practice, two methods of installing sheets are used:

Shifting the next row by several waves.
Without shifting the row with trimming the corners of the sheet.

This use makes it possible to prevent sheets from being overlapped at four angles, which contributes to the formation of cracks. Any of these methods will allow you to properly cover the roof of your house with slate. It should be noted that one wave of the sheet is lower than the opposite extreme wave, and it is painted with a strip of black paint. Installation of slate sheets starts from the eaves; it is very important to correctly align the first sheet using a building level and a plumb line. To mark, string the twine horizontally parallel to the cornice, which serves as a guide for the lower edges of the first row. Vertical twine is stretched from the corner of the roof to the ridge, which avoids bending of subsequent rows of slate. It is imperative to take into account the direction of the main winds in the area. The joint of the vertical ceiling should be located in the direction of the wind, which will eliminate the possibility of the slate sheets being torn off during strong gusts of wind. Installation of sheets can be done both from left to right and from right to left.

Laying slate with offset sheets

The simplest method of laying slate is the technology of ordinary sheet displacement, which eliminates the need to cut corners. The first sheet of the second row is cut longitudinally into one or several waves, and then whole sheets are laid; the last sheet may be subjected to longitudinal cutting.

Laying slate without displacement

When laying slate without offset, the corners of adjacent sheets are trimmed to ensure a tighter fit. The first and last sheets are installed without trimming; the rest need to be preparatory work. A prerequisite is that the corner cuts during installation must have a thermal gap of two to four millimeters and in no case come into contact with each other. For complete clarity, here is a diagram of slate laying with corners trimmed:

To cut the corners, you can use an old hacksaw or a hand-held electric circular saw with a blade designed for cutting stone.

In order to do the trimming correctly, we recommend watching the video below of how a professional does it.

Fastening works

The slate is fastened to the sheathing using screws with a silicone gasket located on the inside of the head; it is highly undesirable to use nails, since during operation they do not stick well to the wood, they become loose and lift, which leads to disruption of the adhesion of the sheets to the sheathing. Each sheet of slate of the first row is secured with two screws in the lower part and one screw in the middle part of the sheet, through holes drilled in the upper wave with a diameter 1-2 mm larger than the thickness of the screw. Under no circumstances should you punch holes, as you may damage the slate or end up with a hole much larger in diameter than the screw head . The upper part of the sheets of the first row will be fixed when installing the second row, while the mounting holes are drilled through two sheets laid with an overlap, which, according to the technology, should be at least 200 mm at a tilt of 25 degrees and at least 150 mm at a tilt of over 30 degrees.

Valley device

Sometimes the shape of the roof contains internal corners, then in this case a valley is required, which is done before covering with slate. The basis is a flooring made of boards on which a waterproofing material is attached, which in turn is covered with galvanized sheet metal. When covering with slate, the sheets are adjusted so that the gap between them has a minimum distance. From the outside, the joint of the slate sheets is covered with a curved strip of galvanized roofing metal.

Connection to chimneys and ventilation pipes

Depending on the location of the pipe, the slope of the slope and other nuances, there may be a sufficient number of options, so let’s consider the main basic option. A sheet of roofing metal with a hole for the pipe is installed in such a way that the upper edge is located under the top sheet of slate, and the lower edge extends onto the underlying slate sheet. Asbestos is laid around the pipe, and the top is covered with a second sheet with a hole for the pipe, but of a larger size. Often, an additional casting of cement mortar is arranged.

Attaching a slate roof to a wall

In some cases, it becomes necessary to install a roof when the upper edge of the slope is adjacent to the wall of the building. To prevent precipitation from getting into the gap between the wall and the slate, especially in the winter-spring period, a flashing made of a strip of roofing iron 400 mm wide is installed and has a longitudinal bend corresponding to the angle of inclination of the slope. One edge of the ebb is attached to the wall with dowels, and the second overlaps the slate sheets on top and is secured through the top wave with screws to the sheathing. This type of roofing is often used on entrances and all kinds of extensions to existing buildings; they usually have no more than two slopes.

Ridge installation

The final stage of roofing work, according to tradition, is the installation of the ridge. Various ready-made ridge elements for constructing a ridge can be easily purchased at any construction market, but if you wish, you can make it yourself from a strip of galvanized roofing metal sheet 400 mm wide using a metal corner and a mallet. The ridge elements are attached to the sheathing through the upper wave of slate with screws. After finishing the roofing work, it wouldn’t hurt to go up to the attic on a sunny day and carefully examine the work of your hands, and if cheerful sunbeams are noticed in the twilight, it means somewhere, something went wrong as you would like. Small cracks and through holes can be easily eliminated with any silicone sealant.

Calculation of material quantity

Before covering the roof with slate, you should calculate how much material is required. To estimate the required number of sheets, so as not to overpay for unnecessary balances, perform the calculations as follows:

Take a tape measure and measure the length of the roof along the eaves. If the roof is still in the project, then take this value from the drawing. Divide the length of the eave overhang by the width of the slate sheet you will use. By increasing this figure by 10% and rounding up to whole numbers, you will get the number of sheets in one tier of the layout .
Measure or find out from the design documentation the length of the roof from the ridge to the edge of the eaves. To calculate the required number of rows, divide this value by the length of the sheet and add 13%. The surcharge compensates for the overlap between the sheets.
By multiplying the number of sheets in one row by the number of tiers, we determine how much material is required to cover the slope. If the roof has two symmetrical slopes, the result is doubled.

Note! In case the sheet is damaged during cutting with your own hands or during transportation, it is better to have a supply of material, 10% is enough. Asbestos dust generated when cutting slate is dangerous to the lungs, so you should only work in a respirator moistened with water.

Manufacturers of thermal insulation materials

The effectiveness of thermal insulation depends not only on compliance with the technology, but also on the quality of the insulation.

When choosing insulation, it is advisable to give preference to products from well-known brands, such as:

Penoplex

Penoplex is a Russian manufacturer that has been producing extruded polystyrene foam since 1998.

Currently it is one of the largest domestic companies.

The products are of high quality, environmental friendliness and durability.

TechnoNIKOL

TechnoNIKOL is another Russian company that produces high-quality extruded polystyrene foam, mineral wool, hydro-vapor barrier and other insulation materials.

The brand is known not only in Russia, but also far beyond its borders.

In particular, we have our own production sites in Italy, Great Britain, the Czech Republic and many other countries in Europe and the CIS.

Paroc

Paroc is one of the largest mineral wool producers in Europe.

The office is located in Finland, but the products are sold in markets of more than 40 countries.

The history of the company goes back more than 80 years.

During this time, the Paroc brand has become synonymous with high quality.

Isover

Isover is a famous French brand that produces mineral wool known throughout the world.

The Saint-Gobain company, which owns the Parok brand, was founded 350 years ago. Currently, it has representative offices in more than 60 countries around the world.

The products are famous for their high quality and the most modern technologies used in their production.

Knauf

Knauf is a German company founded in 1932 that needs no introduction.

It produces a huge amount of building materials.

In particular, thermal insulation materials are also available on the market - polystyrene foam for insulating walls, floors and other surfaces.

Rockwool

Rockwool is an international company headquartered in Denmark.

The company produces stone wool.

The history of Rockwool began in 1909.

Over the 110 years of its existence, it has opened production sites in 28 countries.

Products are supplied to more than 100 countries around the world.

It is very popular in Russia.

Wave slate: varieties and sizes

Dimensional characteristics of eight-wave slate:

width is 1130 mm;
length is 1750 mm;
thickness is 5.8 mm;
The weight of the sheet is 26 kg.

Polyurethane foam

The use of polyurethane foam is undoubtedly a newer technology than the use of polystyrene and mineral wool. This is one of the reasons why it is so much more expensive.

There are two types of polyurethane foam - closed cell foam with coefficients from 0.021 to 0.024 W/(m*K) and open cell foam with coefficients from 0.036 to 0.040 W/(m*K).
To insulate the roof, open-cell foam is used - the thickness of such insulation should be at least 18-20 cm.

PUR foam is sprayed or applied using a special gun. For an experienced team, this insulation option is very fast and reliable - you can create a layer of any thickness that will perfectly cover the insulated surface.

The sprayed foam begins to expand almost immediately, penetrating even the smallest cracks, ensuring the seal of the insulation.

Foam concrete

When installing a flat roof, various materials are used to insulate the roof of the house. These include foam concrete, consisting of

concrete;
cement;
sand;
blowing agent.

Foam material allows you to create durable and reliable roof insulation. Due to its low density, foam concrete does not create high loads on supporting structures and retains heat well. The advantages of the material include

vapor permeability;
non-toxic;
fire safety.

For the installation of foam concrete, a special mobile installation is used. The insulation layer can be from 30 to 150 mm.

Expanded polystyrene

Another popular insulation material is cheaper than mineral wool. However, it is a less flexible material, which makes it difficult to fill the entire space between the rafters. Therefore, you should be especially careful when choosing the sizes of polystyrene foam boards and their exact location.

There are two main types of polystyrene:

EPS - polystyrene foam boards with a thermal conductivity coefficient of 0.030 - 0.042 W/(m*K),
XPS – extruded polystyrene with a coefficient from 0.029 to 0.034 W/(m*K).

A steel grid is installed under the laid polystyrene foam slabs, and a second layer of expanded polystyrene is installed under the rafters to avoid thermal bridges.

Summary comparative table of insulation materials

The above analysis gives the overall picture. For greater clarity, we present the main technical and operational indicators of insulation.

Table 1. Main characteristics of roof insulation.

Insulation / Characteristics	Thermal conductivity, W/(m×°K)	Service life, years	Density, kg/m3	Price
Hard polyurethane foam	0,024-0,035	30	20-80	*****
PPU slabs	0,028-0,030	50-60	40-160	****
Styrofoam	0,037-0,043	20-30	8-35	**
Extruded polystyrene foam	0,028-0,034	More than 50	28-45	*****
Basalt wool	0,038-0,047	More than 50	30-300	***
Expanded clay	0,10-0,18	40-60	210-500	***
Ecowool	0,032-0,041	More than 50	30-75	**
Linen mats	0,034-0,043	50-75	25-50	*****
Glass wool	0,035-0,052	15-25	15-150	***
Sawdust	0,07-0,10	More than 100	200-270	** (*)

***** - high;
**** - above average;
*** - average;
** - low;
* - for free.

The table confirms the conclusions made in the previous section:

There are no alternatives to basalt wool for a pitched roof. As an exception, exotic lovers with money can choose environmentally friendly flax or popular hard polyurethane foam;
Expanded clay, extruded polystyrene foam and basalt wool are suitable for a flat roof. You can also use polyurethane foam boards, but it is expensive.